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Dynamically Loading Link Libraries »
RLibrary
Location:
e32std.h
Link against: euser.lib
RLibrary
Support
Supported from 5.0
Description
Provides a handle to a dynamically loadable DLL.
The class is not intended for user derivation.
Derivation
RHandleBase | Handle to an object |
RLibrary | Provides a handle to a dynamically loadable DLL |
|
Defined in RLibrary:
Close(), DllRefTable(), EntryPoint(), FileName(), GetRamSizes(), LibraryCallList(), Load(), Lookup(), Type()
Inherited from RHandleBase:
Duplicate(),
Handle(),
SetHandle()
Loading DLLs
TInt Load(const TDesC& aFileName,const TUidType& aType);
Description
Loads the named DLL which matches the specified UID type. If
successful, the function increments the usage count by one.
No additional search paths can be specified with this
function.
Parameters
const TDesC& aFileName |
A descriptor containing the name of the DLL to be loaded.
The length of the file name must not be greater than KMaxFileName.
|
const TUidType& aType |
A UID type (a triplet of UIDs) which the DLL must match.
Individual UIDs can contain the KNullUid wild card. |
|
Return value
TInt |
KErrNone, if successful
KErrBadName, if the length of aFileName is greater
than KMaxFileName otherwise one of the system wide error codes
|
|
TInt Load(const TDesC& aFileName,const TDesC& aPath,const TUidType& aType);
Description
Loads the named DLL which matches the specified UID type. If
successful, the function increments the usage count by one.
Parameters
const TDesC& aFileName |
A descriptor containing the name of the DLL to be loaded. The
length of the file name must not be greater than KMaxFileName.
|
const TDesC& aPath |
A descriptor containing a list of path names, each separated
by a semicolon. These paths are searched for the DLL before the standard search
locations. |
const TUidType& aType |
A UID type (a triplet of UIDs) which the DLL must match.
Individual UIDs can contain the KNullUid wild card. |
|
Return value
TInt |
KErrNone, if successful KErrBadName,
if the length of aFileName is greater than
KMaxFileName otherwise one of the system wide error codes |
|
TInt Load(const TDesC& aFileName,const TDesC& aPath=KNullDesC);
Description
Loads the named DLL. If successful, the function increments the
usage count by one.
Parameters
const TDesC& aFileName |
A descriptor containing the name of the DLL to be loaded. The
length of the file name must not be greater than KMaxFileName.
|
const TDesC& aPath |
A descriptor containing a list of path names, each separated by
a semicolon. When specified, these paths are searched for the DLL before the
standard search locations. By default, no pathnames are specified. |
|
Return value
TInt |
KErrNone, if successful KErrBadName,
if the length of aFileName is greater than
KMaxFileName otherwise one of the system wide error codes |
|
void Close();
Description
Closes this DLL. The function decrements the usage count by
one.
This handle must have been used to load the DLL using one of the
Load() functions.
TLibraryFunction Lookup(TInt anOrdinal) const;
Description
Returns a pointer to the function at the specified ordinal within
this DLL.
Parameters
TInt anOrdinal |
The ordinal of the required function in this DLL. This value must be
greater than zero, otherwise the function raises a USER 116 panic. |
|
Return value
TLibraryFunction |
A pointer to the function at position anOrdinal in this
DLL. The value is NULL if there is no function at that ordinal.
|
|
TUidType Type() const;
Description
Returns this DLL's UID type.
The UID type is a property of an EPOC file; for a DLL, its value is set
during the building of that DLL.
Return value
TUidType |
The UID type of this DLL. Note that the first TUid
component of the TUidType has the value
KDynamicLibraryUid. |
|
TLibraryEntry EntryPoint() const;
Description
Returns this DLL's entry point.
Return value
TLibraryEntry |
A pointer to this DLL's entry point |
|
TFileName FileName() const;
Description
Returns the name of this DLL's file.
Return value
TFileName |
This DLL's filename |
|
TInt GetRamSizes(TInt& aCodeSize, TInt& aConstDataSize);
Description
Gets the current size of the code and the const data for this DLL. This
function can be called on a RAM loaded DLL or a ROM based DLL.
Parameters
TInt& aCodeSize |
The current size of the code for a RAM loaded DLL. This is zero for a
ROM based DLL |
TInt& aConstDataSize |
The current size of the const data for a RAM loaded DLL. This is zero
for a ROM based DLL |
|
Return value
TInt |
KErrNone if successful, otherwise one of the system-wide
error codes. |
|
TUint* DllRefTable() const;
Description
Returns a pointer to this DLL's reference table.
Return value
TUint* |
A pointer to this DLL's reference table. This is NULL, if this DLL has
no reference table. |
|
TInt LibraryCallList(TInt& aNumEps, TUint*& aCallList);
Support
Withdrawn in 6.0
Description
Gets a list of entrypoints which become inaccessible to the current
thread when this DLL is unloaded.
Parameters
TInt& aNumEps |
On entry, the number of pointer locations provided by the caller at
aCallList. On return , the number of entry points supplied. |
TUint*& aCallList |
A reference to contiguous memory sufficiently big to
holdaNumEps pointers. This is provided by the caller. On return,
the list of entrypoints. |
|
Return value
TInt |
KErrNone if successful KErrGeneral, if the
number of entrypoints returned by the function is the same as the number of
pointer locations supplied by the caller. This is a hint that there may be more
entrypoints than there is space to rertun them. otherwise, one of the system
wide error codes. |
|
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